1. Field of the Invention
The present invention relates to an absolute encoder.
2. Related Background Art
A conventional absolute encoder comprises an absolute pattern, multi-bit detection elements for detecting the absolute pattern, a multiplexer for sequentially switching and outputting the outputs from the detection elements, and a converter for receiving the output from the multiplexer, and demultiplexing the output to convert it into absolute data. As the absolute pattern, an M-sequence pattern, a gray code pattern, a binary code pattern, and the like are known.
However, in the absolute encoder of this type, since the pattern is detected by sequentially switching the outputs from the detection elements, it takes much time to detect one data. When the moving speed of the encoder is increased, the encoder moves to another data before one data is input, and wrong data may be output. As a result, the speed upon detection of the pattern is limited.